Disassembling a SPECIALIZED BRAIN Fork Cartridge

While doing a service on my Specialized Brain Cartridge & retune I thought someone out there may want to see what is inside one of these cartridges.

The inertia damper is similar to other cartridges in both RockShox forks as well as Fox Terralogic forks. What makes this damper unique is the inertia valve which is built into the base valve of the cartridge. The cartridge still has a midvalve (which is just a check plate) and tunable rebound stack (which is WAY too stiff from the factory).

To tune these cartridges I reduce the threshold shim stack on the base valve which acts as a bypass to the inertia valve. This smooths the transition on square edged bumps that occurs when the inertia valve has not yet had time to open and as a result pressure spikes in the cartridge giving a harsh ride. By reducing the threshold shim stack to the point where the fork barely does not move when pedaling hard while standing the fork functions much better than stock valving.

This is not a disassembly tutorial.

I do not work for Specialized Bicycles nor do I represent them.

Cartridge contents are under extreme pressure and may do serious harm if the cartridge is improperly disassembled.

Cartridge was purchased through a Specialized dealer in Fall of 2015 for full price and has been used since then in a FS Epic for everything from xc racing to heavy trail riding.

I do not tune or service suspension, nor do I work in any part of the bicycle industry.

The fork is off of a 2014 Specialized Epic Comp Carbon, with 2015 Uppers.

The fork and cartridge have been modified to have 110mm of travel from the Brain Fork

specialized brain disassembled
specialized brain inertia valve
specialized brain taken apart